Huawei Quidway S6500 Series Operation Manual page 202

Operation Manual - Routing Protocol
Quidway S6500 Series Ethernet Switches
Chapter 5 Integrated IS-IS Configuration
5.1 Brief Introduction to Integrated IS-IS
Intermediate System-to-Intermediate System (IS-IS) intra-domain routing information
exchange protocol is the dynamic routing protocol used inside the Autonomous System
(AS) issued by the International Organization for Standardization (ISO). In the OSI
model reference, IS equals the router in the TCP/IP model reference. IS-IS protocol,
based on the link state algorithm, uses the Shortest Path First (SPF) algorithm and it is
highly like the Open Shortest Path First (OSPF) protocol.
The integrated IS-IS is an implementation of the IS-IS regulated by IETF on IP.
5.1.1 Terms of IS-IS Routing Protocol
This section introduces IS-IS routing protocol terms.
Intermediate System (IS). IS equals a router of TCP/IP. It is the basic unit in IS-IS
protocol used for propagating routing information and generating routes. In the
following text, IS shares the same meaning with the router.
End System (ES). It equals the host system of TCP/IP. ES does not process the
IS-IS routing protocol, and therefore it can be ignored in the IS-IS protocol.
Routing Domain (RD). A group of ISs exchange routing information with the same
routing protocol in a routing domain.
Area. Area is the division unit in the routing domain.
Link State DataBase (LSDB). All the link states in the network form the LSDB. In
an IS, at least one LSDB is available. The IS uses the SPF algorithm and the
LSDB to generate its own routes.
Link State Protocol Data Unit (LSPDU). In the IS-IS, each IS will generate an LSP
which contains all the link state information of the IS. Each IS collects all the LSPs
in the local area to generate its own LSDB.
Network Protocol Data Unit (NPDU). It is the network layer packets of ISO and
equals the IP packet of TCP/IP.
Designated IS (DIS), is the elected router on the broadcast network, equivalent to
the DR in OSPF.
Network Service Access Point (NSAP) is the network layer address of ISO. It
identifies an abstract network service access point and describes the very network
address for ISO model routing.
Huawei Technologies Proprietary
5-1
Chapter 5 Integrated IS-IS Configuration